Processing of DMSP magnetic data: Handbook of programs, tapes, and datasets

The DMSP F-7 satellite was an operational Air Force meteorological satellite which carried a magnetometer for geophysical measurements. The magnetometer was located within the body of the spacecraft in the presence of large spacecraft fields. In addition to stray magnetic fields, the data have inherent position and time inaccuracies. Algorithms were developed to identify and remove time varying magnetic field noise from the data. These algorithms are embodied in an automated procedure which fits a smooth curve through the data and then identifies outliers and which filters the predominant Fourier component of noise from the data. Techniques developed for Magsat were then modified and used to attempt determination of the spacecraft fields, of any rotation between the magnetometer axes and the spacecraft axes, and of any scale changes within the magnetometer itself. Software setup and usage are documented and program listings are included in the Appendix. The initial and resulting data are archived on magnetic cartridge and the formats are documented

An initial analysis of the data from the Polar Orbiting Geophysical (POGS) Satellite

The Polar Orbiting Geophysical Satellite (POGS) was launched in 1990 to measure the geomagnetic field. POGS data from selected magnetically quiet days was chosen, quality checked and deleted where thought to be erroneous. A time and position correction was applied. The resulting data was fit to a degree 13 spherical harmonic model. Evaluation of the quality of the data indicates that it is sufficient for definition of the low degree (approximately less than 8) portion of the geomagnetic field. Further correction of the data time and position may improve this quality

Geomagnetic model investigations for 1980 - 1989: A model for strategic defense initiative particle beam experiments and a study in the effects of data types and observatory bias solutions

Two suites of geomagnetic field models were generated at the request of Los Alamos National Lab. concerning Strategic Defense Initiative (SDI) research. The first is a progression of five models incorporating MAGSAT data and data from a sequence of batches as a priori information. The batch sequence is: post 1979.5 observatory data, post 1980 land survey and selected aeromagnetic and marine survey data, a special White Sands (NM) area survey by Project Magnet with some additional post 1980 marine survey data, and finally DE-2 satellite data. These models are of 13th deg and order in their main field terms, and deg and order 10 in their first derivative temporal terms. The second suite consists of four models based solely upon post 1983.5 observatory and survey data. They are of deg and order 10 in main field and 8 in a first deg Taylor series. A comprehensive error analysis was applied to both series, which accounted for error sources such as the truncated core and crustal fields, and the neglected Sq and low deg crustal fields. Comparison of the power spectrum of the MGST (10/81) model with those of this series show good agreement

The influence of economic factors on South Africa’s civil engineering consulting firms

Thesis (MEng (Civil Engineering))--Cape Peninsula University of Technology, 2019The infrastructure and construction activity of a country are strong drivers of economic development and the prosperity of a nation. This has been studied and discussed by various scholars such as Ruddock (2008) and Ofori (1990). As the construction industry prospers, employment is provided to many citizens, thereby improving living conditions due to the newly built infrastructure. This state of prosperity is often followed by a state of recession in the economy where jobs are scarce, interest rises and the price of commodities rises. In recent years, it has become glaringly evident that economic cycles have influenced several industrial sectors, including the construction industry and its civil engineering consulting (CEC) firms. In order to ensure that CEC firms remain financially sustainable throughout different macroeconomic cycles, it is necessary to study the economic factors with the highest impact on CEC firms. The aim of this work is to determine the economic factors that affect CEC firms through the different macroeconomic cycles and in which phase of the cycles these economic factors impact CEC firms. To address the aim of the study, mixed methods research was employed. Semi-structured interviews formed part of the qualitative methods used and statistical econometric tests formed part of the quantitative tests used. Seven semi-structured interviews were conducted, with five interviews at CEC firms, one with an employer, in this case South African National Roads Agency (SANRAL), and one with the Consulting Engineers of South Africa (CESA) association. The econometric data analysis made use of ADF Unit Root tests, Johansen Co-Integration tests and Granger Causality tests. The quantitative results showed that gross domestic product (GDP) and gross fixed capital formation (GFCF) of total investment indicate a change in total revenue of construction consulting firms. The Granger Causality results showed that construction value added (CVA) and GFCF of construction investment tend not to cause nor indicate a change in revenue of construction consulting firms, and vice-versa. The semi-structured interviews identified 16 economic factors that affect CEC firms. These factors were determined to be caused primarily by the South African economic activity, construction activity and CEC industry. It was observed that these factors can occur in different phases of a macroeconomic cycle, with business confidence and foreign investment having the highest influence during the recovery phase, capacity of firms and tender roll out having the highest influence during the peak phase, training of governmental staff and diversification having the highest influence during the downswing cycle, and strategic planning of CEC firms having the highest influence during the through phase of the cycle

Evidence for a Low Bulk Crustal Density for Mars from Gravity and Topography

Knowledge of the average density of the crust of a planet is important in determining its interior structure. The combination of high-resolution gravity and topography data has yielded a low density for the Moons crust, yet for other terrestrial planets the resolution of the gravity field models has hampered reasonable estimates. By using well-chosen constraints derived from topography during gravity field model determination using satellite tracking data, we show that we can robustly and independently determine the average bulk crustal density directly from the tracking data, using the admittance between topography and imperfect gravity. We find a low average bulk crustal density for Mars, 2582 209 kgm3. This bulk crustal density is lower than that assumed until now. Densities for volcanic complexes are higher, consistent with earlier estimates, implying large lateral variations in crustal density. In addition, we find indications that the crustal density increases with depth

CM5, a pre-Swarm comprehensive geomagnetic field model derived from over 12yr of CHAMP, Ørsted, SAC-C and observatory data

A comprehensive magnetic field model named CM5 has been derived from CHAMP, Ørsted and SAC-C satellite and observatory hourly-means data from 2000 August to 2013 January using the Swarm Level-2 Comprehensive Inversion (CI) algorithm. Swarm is a recently launched constellation of three satellites to map the Earth's magnetic field. The CI technique includes several interesting features such as the bias mitigation scheme known as Selective Infinite Variance Weighting (SIVW), a new treatment for attitude error in satellite vector measurements, and the inclusion of 3-D conductivity for ionospheric induction. SIVW has allowed for a much improved lithospheric field recovery over CM4 by exploiting CHAMP along-track difference data yielding resolution levels up to spherical harmonic degree 107, and has allowed for the successful extraction of the oceanic M2 tidal magnetic field from quiet, nightside data. The 3-D induction now captures anomalous Solar-quiet features in coastal observatory daily records. CM5 provides a satisfactory, continuous description of the major magnetic fields in the near-Earth region over this time span, and its lithospheric, ionospheric and oceanic M2 tidal constituents may be used as validation tools for future Swarm Level-2 products coming from the CI algorithm and other dedicated product algorithm

An analysis of hunting, fishing, and boating privilege suspensions enacted by the South Carolina Department of Natural Resources

The purpose of this research project is to analyze violations of the natural resources and boating laws to identify the characteristics of individuals whose privileges to hunt, trap, fish, and operate a watercraft were suspended